WASHINGTON -- Here's a safety tip from your government: Trash those unwanted prescription drugs with kitty litter or coffee grounds to keep them from falling into the wrong hands -- and mouths.

New federal prescription drug disposal guidelines recommend mixing unused, unneeded or expired drugs with undesirable substances -- like cat litter or coffee grounds -- and tossing them in the trash in nondescript containers. Doing so should curb prescription drug abuse and protect lakes and streams from contamination, the White House and government health and environment officials said.

"Following these new guidelines will protect our nation's waterways and keep pharmaceuticals out of the hands of potential abusers," Environmental Protection Agency administrator Stephen L. Johnson said Wednesday.

Drugs should be flushed down the toilet only if the label says it's safe to do so, according to the guidelines. Some pharmacies also collect drugs for safe disposal.

The government warned that abuse of prescription drugs is increasingly common among teens and young adults. Often those drugs are taken from the medicine cabinets of relatives or friends.

While flushing drugs down the toilet can stem that sort of abuse, it also can create environmental problems.

Recent U.S. Geological Survey studies have shown that a wide range of pharmaceuticals and other compounds survive wastewater treatment and later are discharged into lakes, streams and other bodies of water across North America. The USGS research found antidepressants and their byproducts, for example, are being released into the environment at concentrations that may affect aquatic life.